public void LightingUsesLightIntensityToAttenuateColor(
double intensity,
double r,
double g,
double b)
{
var w = new DefaultWorld();
w.Lights = new ILight[]
{
new PointLight(Vector4.CreatePosition(0, 0, -10), Color.White),
};
var shape = w.Objects[0];
shape.Material.Ambient = 0.1;
shape.Material.Diffuse = 0.9;
shape.Material.Specular = 0;
shape.Material.Color = new Color(1, 1, 1);
var pt = Vector4.CreatePosition(0, 0, -1);
var eyev = Vector4.CreateDirection(0, 0, -1);
var normalv = Vector4.CreateDirection(0, 0, -1);
var result = shape.Material.Li(
shape,
w.Lights[0],
pt,
eyev,
normalv,
intensity);
var expected = new Color(r, g, b);
Assert.Equal(expected, result);
}
public static Tuple <World, Camera> Example11(int width, int height)
{
var world = new World();
var hex = Hexagon.Create();
world.Objects.Add(hex);
var light = new PointLight(
Vector4.CreatePosition(-10, 10, -10),
Color.White);
world.Lights.Add(light);
var camera = new Camera(width, height, Math.PI / 4.2)
{
Transform = Transform.View(
Vector4.CreatePosition(-4, 5, -3),
Vector4.CreatePosition(0, 0.5, 0),
Vector4.CreateDirection(0, 1, 0)),
ProgressMonitorFactory =
(_rows, _cols) => new DefaultProgressMonitor(),
};
return(Tuple.Create(world, camera));
}
public void ShadeIntersectionInShadow()
{
var w = new World();
w.Lights.Add(
new PointLight(
Vector4.CreatePosition(0, 0, -10),
Color.White));
var s1 = new Sphere();
var s2 = new Sphere()
{
Transform = Transform.Translate(0, 0, 10),
};
w.Objects.Add(s1);
w.Objects.Add(s2);
var r = new Ray(Vector4.CreatePosition(0, 0, 5), Vector4.CreateDirection(0, 0, 1));
var i = new Intersection(4, s2);
var comps = i.Precompute(r);
var c = w.Render(comps, 5);
var expected = new Color(0.1, 0.1, 0.1);
Assert.Equal(expected, c);
}
public void FindingN1AndN2AtVariousIntersections(int index, double n1, double n2)
{
var a = new GlassSphere()
{
Transform = Transform.Scale(2, 2, 2),
};
var b = new GlassSphere()
{
Transform = Transform.Translate(0, 0, -0.25),
};
var c = new GlassSphere()
{
Transform = Transform.Translate(0, 0, 25),
};
a.Material.RefractiveIndex = 1.5;
b.Material.RefractiveIndex = 2.0;
c.Material.RefractiveIndex = 2.5;
var r = new Ray(Vector4.CreatePosition(0, 0, -4), Vector4.CreateDirection(0, 0, 1));
var xs = IntersectionList.Create(
new Intersection(2, a),
new Intersection(2.75, b),
new Intersection(3.25, c),
new Intersection(4.75, b),
new Intersection(5.25, c),
new Intersection(6, a));
var comps = xs[index].Precompute(r, xs);
Assert.Equal(n1, comps.N1);
Assert.Equal(n2, comps.N2);
}
public void IntersectRayWithNonEmptyGroup()
{
var g = new Group();
var s1 = new Sphere();
var s2 = new Sphere()
{
Transform =
Transform.Translate(0, 0, -3),
};
var s3 = new Sphere()
{
Transform =
Transform.Translate(5, 0, 0),
};
g.Add(s1);
g.Add(s2);
g.Add(s3);
var r = new Ray(Vector4.CreatePosition(0, 0, -5), Vector4.CreateDirection(0, 0, 1));
var xs = g.LocalIntersect(r);
Assert.Equal(4, xs.Count);
Assert.Equal(s2, xs[0].Object);
Assert.Equal(s2, xs[1].Object);
Assert.Equal(s1, xs[2].Object);
Assert.Equal(s1, xs[3].Object);
}
public void TestDotProductOfTwoVector4s()
{
var a = Vector4.CreateDirection(1, 2, 3);
var b = Vector4.CreateDirection(2, 3, 4);
Assert.Equal(20, a.Dot(b));
}
public void TestTranslationDoesNotAffectVectors()
{
var t = Transform.Translate(5, -3, 2);
var v = Vector4.CreateDirection(-3, 4, 5);
Assert.Equal(v, t * v);
}
public void ComputingTheNormalVectorOnCone()
{
var shape = new Cone();
var cases = new[]
{
new
{
point = Vector4.CreatePosition(0, 0, 0),
normal = Vector4.CreateDirection(0, 0, 0),
},
new
{
point = Vector4.CreatePosition(1, 1, 1),
normal = Vector4.CreateDirection(1, -Math.Sqrt(2), 1),
},
new
{
point = Vector4.CreatePosition(-1, -1, 0),
normal = Vector4.CreateDirection(-1, 1, 0),
}
};
foreach (var c in cases)
{
var n = shape.GetLocalNormal(c.point);
Assert.Equal(c.normal, n);
}
}
public void ConvertNormalFromObjectSpaceToWorldSpace()
{
var g1 = new Group()
{
Transform = Transform.RotateY(Math.PI / 2),
};
var g2 = new Group()
{
Transform = Transform.Scale(1, 2, 3),
};
g1.Add(g2);
var s = new Sphere()
{
Transform = Transform.Translate(5, 0, 0),
};
g2.Add(s);
var v = Vector4.CreateDirection(Math.Sqrt(3) / 3, Math.Sqrt(3) / 3, Math.Sqrt(3) / 3);
var n = s.NormalToWorld(v);
const double eps = 0.0001;
var comparer = Vector4.GetEqualityComparer(eps);
var expected = Vector4.CreateDirection(0.2857, 0.4286, -0.8571);
Assert.Equal(expected, n, comparer);
}
public void RefractedColorWithRefractedRay()
{
var w = new DefaultWorld();
var a = w.Objects[0];
a.Material.Ambient = 1.0;
a.Material.Pattern = new TestPattern();
var b = w.Objects[1];
b.Material.Transparency = 1.0;
b.Material.RefractiveIndex = 1.5;
var r = new Ray(
Vector4.CreatePosition(0, 0, 0.1),
Vector4.CreateDirection(0, 1, 0));
var xs = IntersectionList.Create(
new Intersection(-0.9899, a),
new Intersection(-0.4899, b),
new Intersection(0.4899, b),
new Intersection(0.9899, a));
var comps = xs[2].Precompute(r, xs);
var c = w.GetRefractedColor(comps, 5);
var expected = new Color(0, 0.99888, 0.04725);
const double eps = 0.0001;
var comparer = Color.GetEqualityComparer(eps);
Assert.Equal(expected, c, comparer);
}
public void TestVectorFactoryMethod()
{
var v = Vector4.CreateDirection(4, -4, 3);
var expected = new Vector4(4, -4, 3, 0);
Assert.Equal(expected, v);
}
public void FindNormalOnChildObject()
{
var g1 = new Group()
{
Transform = Transform.RotateY(Math.PI / 2),
};
var g2 = new Group()
{
Transform = Transform.Scale(1, 2, 3),
};
g1.Add(g2);
var s = new Sphere()
{
Transform = Transform.Translate(5, 0, 0),
};
g2.Add(s);
var p = Vector4.CreatePosition(1.7321, 1.1547, -5.5774);
var n = s.GetNormal(p);
const double eps = 0.0001;
var comparer = Vector4.GetEqualityComparer(eps);
var expected = Vector4.CreateDirection(0.2857, 0.4286, -0.8571);
Assert.Equal(expected, n, comparer);
}
public void AreaLightWithJitteredSamples(
double px,
double py,
double pz,
double result)
{
var w = new DefaultWorld();
var corner = Vector4.CreatePosition(-0.5, -0.5, -5);
var v1 = Vector4.CreateDirection(1, 0, 0);
var v2 = Vector4.CreateDirection(0, 1, 0);
var light = new AreaLight(
corner,
v1,
2,
v2,
2,
Color.White)
{
Jitter = new Sequence(0.7, 0.3, 0.9, 0.1, 0.5),
};
var pt = Vector4.CreatePosition(px, py, pz);
var intensity = light.GetIntensity(pt, w);
Assert.Equal(result, intensity);
}
public void FindSinglePointOnJitteredAreaLight(
double u,
double v,
double rx,
double ry,
double rz)
{
var corner = Vector4.CreatePosition(0, 0, 0);
var v1 = Vector4.CreateDirection(2, 0, 0);
var v2 = Vector4.CreateDirection(0, 0, 1);
var light = new AreaLight(
corner,
v1,
4,
v2,
2,
Color.White)
{
Jitter = new Sequence(0.3, 0.7),
};
var pt = light.GetPoint(u, v);
var expected = Vector4.CreatePosition(rx, ry, rz);
Assert.Equal(expected, pt);
}
public void TestMagnitudeOfNormalizedVector()
{
var v = Vector4.CreateDirection(1, 2, 3);
var norm = v.Normalize();
Assert.Equal(1, norm.Magnitude(), 6);
}
public void ShadeWithReflectiveTransparentMaterial()
{
var w = new DefaultWorld();
var r = new Ray(
Vector4.CreatePosition(0, 0, -3),
Vector4.CreateDirection(0, -Math.Sqrt(2) / 2, Math.Sqrt(2) / 2));
var floor = new Plane();
floor.Transform = Transform.Translate(0, -1, 0);
floor.Material.Reflective = 0.5;
floor.Material.Transparency = 0.5;
floor.Material.RefractiveIndex = 1.5;
var ball = new Sphere();
ball.Transform = Transform.Translate(0, -3.5, -0.5);
ball.Material.Color = new Color(1, 0, 0);
ball.Material.Ambient = 0.5;
w.Objects.Add(floor);
w.Objects.Add(ball);
var xs = IntersectionList.Create(
new Intersection(Math.Sqrt(2), floor));
var comps = xs[0].Precompute(r, xs);
var c = w.Render(comps, 5);
var expected = new Color(0.93391, 0.69643, 0.69243);
const double eps = 0.00001;
var comparer = Color.GetEqualityComparer(eps);
Assert.Equal(expected, c, comparer);
}
public void TestMultiplyByTheInverseOfScalingMatrix()
{
var t = Transform.Scale(2, 3, 4).Inverse();
var v = Vector4.CreateDirection(-4, 6, 8);
var expected = Vector4.CreateDirection(-2, 2, 2);
Assert.Equal(expected, t * v);
}
public void TestScalingMatrixAppliedToVector()
{
var t = Transform.Scale(2, 3, 4);
var p = Vector4.CreateDirection(-4, 6, 8);
var expected = Vector4.CreateDirection(-8, 18, 32);
Assert.Equal(expected, t * p);
}
public void TestColorWhenRayMisses()
{
var w = new DefaultWorld();
var r = new Ray(Vector4.CreatePosition(0, 0, -5), Vector4.CreateDirection(0, 1, 0));
var c = w.Trace(r, 5);
Assert.Equal(Color.Black, c);
}
public void TestRayMissesSphere()
{
var r = new Ray(Vector4.CreatePosition(0, 2, -5), Vector4.CreateDirection(0, 0, 1));
var s = new Sphere();
var xs = s.Intersect(r);
Assert.Empty(xs);
}
public void IntersectRayWithEmptyGroup()
{
var g = new Group();
var r = new Ray(Vector4.CreatePosition(0, 0, 0), Vector4.CreateDirection(0, 0, 1));
var xs = g.LocalIntersect(r);
Assert.Empty(xs);
}
public void TestNormalOnSphereAtPointOnXAxis()
{
var s = new Sphere();
var n = s.GetNormal(Vector4.CreatePosition(1, 0, 0));
var expected = Vector4.CreateDirection(1, 0, 0);
Assert.Equal(expected, n);
}
public void HitWhenIntersectionOnOutside()
{
var r = new Ray(Vector4.CreatePosition(0, 0, -5), Vector4.CreateDirection(0, 0, 1));
var shape = new Sphere();
var i = new Intersection(4, shape);
var comps = i.Precompute(r);
Assert.False(comps.Inside);
}
public void RayMissesCsgObject()
{
var c = new Csg(Operation.Union, new Sphere(), new Cube());
var r = new Ray(Vector4.CreatePosition(0, 2, -5), Vector4.CreateDirection(0, 0, 1));
var xs = c.LocalIntersect(r);
Assert.Empty(xs);
}
public void TestSubtractVectorFromZeroVector()
{
var zero = Vector4.CreateDirection(0, 0, 0);
var v = Vector4.CreateDirection(1, -2, 3);
var expected = Vector4.CreateDirection(-1, 2, -3);
Assert.Equal(expected, zero - v);
}
public void IntersectWithCoplanarRay()
{
var p = new Plane();
var r = new Ray(Vector4.CreatePosition(0, 0, 0), Vector4.CreateDirection(0, 0, 1));
var xs = p.LocalIntersect(r);
Assert.Empty(xs);
}
public void TestSubtractTwoVectors()
{
var v1 = Vector4.CreateDirection(3, 2, 1);
var v2 = Vector4.CreateDirection(5, 6, 7);
var expected = Vector4.CreateDirection(-2, -4, -6);
Assert.Equal(expected, v1 - v2);
}
public void TestSubtractTwoPoints()
{
var p1 = Vector4.CreatePosition(3, 2, 1);
var p2 = Vector4.CreatePosition(5, 6, 7);
var expected = Vector4.CreateDirection(-2, -4, -6);
Assert.Equal(expected, p1 - p2);
}
public void TestSubtractVectorFromPoint()
{
var p = Vector4.CreatePosition(3, 2, 1);
var v = Vector4.CreateDirection(5, 6, 7);
var expected = Vector4.CreatePosition(-2, -4, -6);
Assert.Equal(expected, p - v);
}
public void TestReflectVectorApproachingAt45Degrees()
{
var v = Vector4.CreateDirection(1, -1, 0);
var n = Vector4.CreateDirection(0, 1, 0);
var r = v.Reflect(n);
var expected = Vector4.CreateDirection(1, 1, 0);
Assert.Equal(expected, r);
}